As if you weren't uneasy enough about hormone therapy, a new study adds another layer to the risks. An uncommon type of breast cancer may be linked to combined hormone therapy, and the likelihood of getting it seems to rise even faster than researchers thought. The risk of lobular breast cancer, which is more difficult to detect on mammogram than other types of breast cancer, quadruples after only 3 years of combined estrogen/progestin therapy. It was previously thought that the risk rose after being on combined therapy for 5 years. This finding was the result of a study from the Fred Hutchinson Cancer Research Center in Seattle, Washington.

While this type of cancer accounts for only 15 percent of all breast cancers, it is important to understand the risk because it is harder to detect, and can therefore become advanced before it is diagnosed. The American Cancer Association recommendations for screening are a good starting place for keeping a watch on your breast health, whether you are on hormone therapy or not.

There are no new recommendations about hormone therapy as a result of this study, but it reinforces the current recommendation that women use hormone therapy at the lowest doses possible for the least amount of time necessary. If you are a menopausal woman taking hormone therapy, check with your medical provider to design an approach that will work for your symptoms and risk factors.

Researchers did not see an increased risk for this cancer in women who were on estrogen therapy without progestin, or in women who were not on any hormone therapy at all.